Energy taken up by co-seismic chemical reactions during a large earthquake: An example from the 1999 Taiwan Chi-Chi earthquake

Frictional heat in a fault zone during earthquake slip transiently induces chemical reactions that may use energy released during the earthquake. We estimated the energy used by such reactions (EC) by a numerical analysis incorporating frictional heat, thermal diffusion, chemical kinetics, and energy conservation, and found that EC has an auto-feedback effect that inhibits temperature rise in fault zone. During the 1999 Taiwan Chi-Chi earthquake, estimated EC was 0.43 MJ/m(2), corresponding to 0.79% of the frictional heat generated. This low percentage probably reflects the low initial concentrations of reactive materials. However, in the case of a fault with abundant reactive materials, EC could reach > 50% of the frictional heat and the auto-feedback effect could be large. At this case EC is a nonnegligible component on earthquake energy budget and can affect fault mechanics. Citation: Hamada, Y., T. Hirono, W. Tanikawa, W. Soh, and S.-R. Song (2009), Energy taken up by co-seismic chemical reactions during a large earthquake: An example from the 1999 Taiwan Chi-Chi earthquake, Geophys. Res. Lett., 36, L06301, doi: 10.1029/2008GL036772.